To survive and reproduce, organisms need to be adapted to their environments. These adaptations can either be:

  • Structural
  • Behavioural
  • Functional

Structural adaptations

Structural adaptations are the physical features that give an organism a survival advantage. These might include an organism’s shape or colour.

For example, foxes that live in warm regions have long ears, a long tail and wide body surfaces.

This increases the surface area of skin that is exposed to the surroundings. The skin of these foxes contains warm circulating blood, which results in more heat loss to the cooler surroundings.

Behavioural adaptations

Behavioural adaptations are the way an organism behaves or acts, which gives them an advantage.

For example:

  • Some birds migrate to warmer regions during the winter
  • Wolves work together in packs to hunt and kill prey

Functional adaptations

Functional adaptations are internal processes or systems in an organism that give it a survival advantage. For example, camels store fat inside their humps, which they can break down later for energy.

Another example can be seen with chameleons, which change colour based on their environment and scenario, allowing them to camouflage and blend into their surroundings.

This adaptation helps them avoid detection by predators.


Extremophiles are organisms that are adapted to live in extreme environments. They are usually in areas with very high or low temperatures, pressures, or high salt concentrations.

The giant tube worm is an extremophile that is found near deep-sea hydrothermal vents. In these areas, the conditions are extremely hot, under high pressure and there is no sunlight. Within its gut, the giant tube worm hosts a significant number of bacteria, which convert gases into organic molecules for the worm to eat.

  • What makes these ecosystems unique is that their food chains and webs do not start with photosynthesising plants or algae.

The adaptations of such extremophiles allow them to survive in these locations. However, many cannot survive under moderate conditions.

You’ve used 10 of your 10 free revision notes for the month

Sign up to get unlimited access to revision notes, quizzes, audio lessons and more

Sign up